10 FOSSIL FISHES OF SOUTHERN CALIFORNIA 



affinity with AMMODYTES, a group in which the ventrals, when present, 

 are attached below the pectoral fins. The type specimen was presented 

 to Stanford University by its discoverer, the late Dr. Stephen Bowers. 



Besides this specimen two others seem referable to the same species. 

 No. LXXIX from Brown's Canon is the vertebral column of a rather 

 larger fish ; the vertebrae are very strong, with long and strong processes. 

 XC from Brown's Canon is a strong tail with twenty vertebras and a 

 very strong, well- forked caudal fin as long as the last seventeen vertebrae. 

 XCIV is an uncertain fragment from the same beds. 



The name RHOMURUS is from 'pcouii, strength; OVQ<X, tail. 



Family SCOMBRID^E. 



6. Auxides sanctae-monicae Jordan, new genus and species. 



(Plate V, fig. 2) 

 (Type of the genus: THYNNUS PROPTERYGIUS Agassiz.) 



From the sandstone of Brown's Canon in the Sierra Santa Monica, 

 I have three broken sections of a mackerel-like fish about sixteen inches 

 in length, which represents a genus new to science and apparently a new 

 species also. A third specimen from Brown's Canon presents a crushed 

 head with a part of the body as far as the end of the first dorsal fin. 

 The torso represented anterior to the break in the accompanying figure 

 (No. LI, Stanford Geological Collections, from Brown's Canon) is 

 taken as the type of the species. It is not certain that the posterior part 

 belonged to the same actual individual, but it is assuredly of the same 

 species and approximately the same size. It is this posterior part which 

 is noticed as No. 41, "a Scombroid fish," on page 133 of my "Fossil 

 Fishes of California." A much abraded head of the same species is 

 represented on page 128 of the same paper, figure 22, as a "Pterothrissoid 

 fish." Fragments are in the collection from Brown's Canon, Moore's 

 Canon, and Soledad Pass. 



Head 4^4 in length to base of caudal ; depth at first dorsal 4% ; 

 dorsal with seven spines, the longest probably a shade more than half 

 head; dorsals widely separated, the interspace probably two-thirds head; 

 this not certain, as the soft dorsal is mostly obliterated; caudal deeply 

 forked, its tips broken, angle of the lobes about as in SCOMBER, much 

 less than in Auxis. Vertebrae about 12.+ 14 = 26, the number not quite 

 certain, as two or three may be lost in the break, but certainly less than 

 in SCOMBER (31) ; all the vertebrae normal in form, with no trace of the 

 peculiar "trellised" structure seen in EUTHYNNUS and Auxis. Neural 

 and haemal spines large and strong. Angle of preopercle enlarged, 

 forming a conspicuous bony plate with strong radiating ridges. Mouth 



